WIMBLEDON, England  The last player to beat Roger Federer at Wimbledon has a law degree, wrote a thesis about the men's tour and cracked the top 10 two years ago at age 22.

Among his achievements, however, Mario Ancic is best known for his upset victory over Federer in 2002.

"Since then he hasn't lost on grass," Ancic said. "Unbelievable."

They meet again in the quarterfinals Wednesday, with the top-ranked Federer three wins from a sixth consecutive Wimbledon title. Since the loss to Ancic in the first round six years ago, Federer has won 63 consecutive grass-court matches, including 38 at the All England Club.

"I can sit here and talk stories about the great win and how I beat Roger Federer," Ancic said. "But actually it wasn't Roger Federer as we know him today."

Federer and his nemesis, No. 2-ranked Rafael Nadal, were the only top-10 players to reach the men's quarterfinals, keeping them on course to meet in the final for the third year in a row.

Nadal said he feared being forced to quit after he stumbled and hurt his right leg Monday in the second game of a victory over Mikhail Youzhny. After being treated and taped by a trainer, Nadal went on to an easy win.

Nadal said he was relieved to be given medical clearance when he was examined by a doctor after the match, and he was seen bounding happily down a stairway at the club Tuesday.

His quarterfinal opponent will be No. 12-seeded Andy Murray, trying to become the first British man to win Wimbledon since Fred Perry in 1936. The winner of that match will advance to the semifinals against the winner of the match with the improbable pairing of No. 94-ranked Rainer Schuettler and No. 145-ranked Arnaud Clement.

Two-time major champion Marat Safin will play in his first Grand Slam quarterfinal since winning the Australian Open in 2005. His opponent will be No. 31-seeded Feliciano Lopez.

All eight Wimbledon quarterfinalists are from Europe, the first time that has occurred at a Grand Slam tournament in the Open era.

Federer's last loss at the All England Club came the year after his upset win at Wimbledon against seven-time champion Pete Sampras. Federer had yet to win a major championship but was No. 7-seeded and touted as a title contender, while Ancic was an 18-year-old qualifier ranked 154th and playing his first Grand Slam match.

During his Wimbledon reign, Federer has lost only eight of 122 sets, sweeping all 12 this year. He has won the opening set in 37 of his 38 victories, the lone exception being the 2004 final against Andy Roddick. He has beaten 31 players, including six Grand Slam champions  Nadal, Safin, Roddick, Lleyton Hewitt, Thomas Johansson and Juan Carlos Ferrero  as well as Ancic in a 2006 rematch.